Field of the Invention
The invention relates generally to case packing apparatus. More particularly, it concerns an improved conveyor apparatus for providing accurately and selectively spaced product for handling by a case packer.
A problem encountered in product handling today is presented by the need to safely move a high quantity of product from a conveyor belt into one or more shipping containers in an efficient and orderly fashion. This problem is accentuated by today""s high speed packaging machines and high speed conveyor belts that are capable of producing and moving a very high quantity of products, such as bagged products, along a conveyor belt to a case packer for movement into the boxes or cases. In particular, while the packaging machines and conveyor systems are capable of producing and providing a large quantity of product rapidly to a case packer, the loading process often bogs down because the case packers cannot load the cases as rapidly as the product can be supplied. An obvious solution is to purchase multiple case packers and route product to the various case packers. While this solution is xe2x80x9cobvious,xe2x80x9d the extreme expense of such a solution is also obvious. It is therefore desirable to increase the efficiency of the case packers so that each case packer can handle greater quantities of product.
One of the problems encountered by the case packers exists because the timing of the supply of products on a conveyor belt is too rapid for the loading apparatus. Current equipment often uses gantry robot vacuum head assemblies to lift products from a conveyor belt and deposit the products in a case. These assemblies, however, generally require that the product be stopped on the conveyor belt so that the product can be picked up and placed. The stoppage of product, lifting of product, and placing of product usually takes more time than is permitted by the spacing of the product on a feed conveyor belt.
Another common problem encountered in loading products such as bagged products using loading mechanisms such as gantry robots having a plurality of vacuum heads is that the bags of product must be properly spaced on the conveyor belt to ensure that each bag is lined up underneath a respective vacuum head when the vacuum heads are lowered to pick up the products. Such accurate spacing is seldom presented by the normal operation of the conveying system within a manufacturing plant. It is therefore necessary to provide a conveying apparatus that will cause the packages to have the required selective spacing.
Accordingly, it is desirable to provide a conveying system that delivers bags to a loading area wherein the bags have an accurate and desired spacing for handling. It is still further desirable to provide an apparatus that can provide bags having such spacing, while at the same time handling the high quantity of bags currently encountered and desired in many package handling environments.
The present invention provides such a conveyor apparatus for spacing the product through the provision of a conveyor assembly for providing selectively spaced products for packing that includes a timing conveyor belt comprising a first motor for driving the timing conveyor belt. A pick conveyor belt including a pick motor for selectively driving the pick conveyor belt is operatively aligned with the timing belt for receiving product from the timing belt. A sensor is operatively associating with the timing conveyor belt and adapted to sense the arrival of each product on the timing conveyor belt. A controller is operatively connected to the first motor, the pick motor, and the sensor and is adapted to vary the speed of the pick motor (and the pick conveyor belt thereby) relative to the speed of the first motor (and the timing conveyor belt thereby) to provide selective spacing between products on the pick conveyor belt.
In a preferred aspect of this embodiment, the controller repeatedly increases or decreases the speed of the pick motor in response to the presence or absence of product on the timing conveyor belt in order to adjust the travel of the pick conveyor belt to provide the desired spacing.
In an alternative embodiment of the present invention adapted for higher speed supply of product, a conveyor assembly is provided for supplying accurately and selectively spaced products for packing cases. The conveyor assembly includes a feed conveyor belt for supplying products, and first and second pick conveyor belts. A diverter conveyor belt is positioned between the feed conveyor belt and the first and second pick conveyor belts and adapted to selectively route products from the feed conveyor belt to the first pick conveyor belt or to the second pick conveyor belt. A first pick motor is operatively connected with the first pick conveyor belt for controlling the speed of the first pick conveyor belt. A second pick motor is operatively connected with the second pick conveyor belt for controlling the speed of the second pick conveyor belt. A sensor, such as a photo cell, is operatively associated with the diverter belt for sensing each product as it passes over a selected point on the diverter conveyor belt. The conveyor assembly further includes a controller operatively connected to the sensor, to the first pick motor, and to the second pick motor for selectively varying the speed of the first and second pick motors to provide a desired spacing of products on the first and second pick belts.
In a preferred aspect of this embodiment of the invention, the first and second pick belts are positioned substantially parallel to each other. The diverter conveyor belt is then adapted to selectively align the conveyor belt with either the first pick belt or the second pick belt in order to selectively deliver product or groups of product to either the first pick belt or to the second pick belt.
In a still more preferred aspect of this embodiment of the present invention, the conveyor assembly further includes a first diverter motor operatively associated with the diverter conveyor belt for controlling the speed of the diverter conveyor belt. The controller is then also connected to the first diverter motor for selectively varying the speed of the first and second pick motors relative to the speed of the first diverter motor to provide a desired spacing of products on the first and second pick conveyor belts.
In a yet more preferred aspect of this embodiment of the present invention, the controller makes frequent periodic adjustments to the first or second pick motor speed in order to accurately adjust for random spacing of product on the feed and diverter belts.
In the most preferred aspect of the embodiment of the present invention, the conveyor assembly comprises a gantry robot vacuum head assembly including a plurality of robot vacuum heads selectively spaced in a line. The assembly is adapted to move sequentially from a first position over the first pick belt to a second position over a row of cases and then to a third position over the second pick belt, following which it returns to substantially the second position over the row of cases. The sequence allows the gantry robot vacuum head assembly to lift products off the first pick belt and deposit them into cases, and then lift products off the second pick belt and deposit them into cases.
Accordingly, by diverting a selected number of products first to the first belt, where the products are selectively spaced and stopped for loading, and then to the second pick belt where the products are selectively spaced (while the first set of products are being removed from the first pick belt), the apparatus of the present invention allows essentially continuous feed of products at a very high speed for removal and loading by a gantry robot vacuum head assembly. In particular, the use of two pick belts allows a first row of products to be positioned on the first pick belt, after which the first pick belt is momentarily stopped to allow the gantry robot assembly to remove and place the product into cases. While the gantry robot vacuum head assembly is placing the product in the cases, product is still being fed, albeit to the second pick belt, where the product is again accurately and selectively spaced for the gantry robot vacuum head assembly. The gantry robot assembly then moves to the product on the second pick belt while product is being fed to the now vacant first pick belt. This process is repeated until a desired quantity of product is packed into the cases.
Accordingly, the present invention also provides a method for packing cases with products. The method comprises the steps of (a) transporting a plurality of products on a feed conveyor belt to a diverter conveyor belt. The product is then sensed at a selected point once it is on the diverter conveyor belt. The diverter conveyor belt is aligned with a first pick belt for delivery of a selected number of products to the first pick belt. The first pick belt is advanced at a desired speed determined by the speed of the diverter conveyor belt and the desired spacing between products on the first pick belt. Once the desired quantity of products have been delivered to the first pick belt and selectively spaced, the diverter belt is then aligned with a second pick belt while the first pick belt is stopped. The second pick belt is advanced to the desired speed to provide selective spacing between the products in the same manner that the first pick belt was advancedxe2x80x94and the speed of the second pick belt depends upon the spacing of product on the diverter belt, the speed of the diverter belt and the desired spacing on the second pick belt. At the same time, the products on the first pick conveyor belt are lifted from the first pick conveyor belt and placed in cases and the first pick conveyor belt is restarted. Once the desired quantity of products has been delivered to the second pick conveyor belt, the diverter belt is then shifted back to the first pick conveyor belt while the second pick conveyor belt is stopped. The first pick conveyor belt is then advanced at a desired speed to provide the selected spacing using the same parameters as before when spaced product was provided to the first pick conveyor belt. At the same time, the products on the second pick conveyor belt are removed from the second pick conveyor belt and placed into cases. This process of alternating the supply of product between the first pick conveyor belt and the second pick conveyor belt is repeated until the desired quantity of product is loaded into the cases.
Accordingly, the present invention provides a conveyor assembly that allows essentially continuous feed of product at a high speed to a case packing apparatus such as a gantry robot assembly, while at the same time providing selective and accurate spacing for such product suitable for use of a gantry robot vacuum head assembly.
These and other advantages of the present invention will be more fully appreciated by the following detailed description of the invention.